Thermo Scientific™ Fish Serum Blocking Buffer

Catalog No.	Quantity
PI37527	500 mL
PI37527X3	3 x 500 mL

Catalog No. PI37527 Supplier Thermo Scientific™ Supplier No. 37527

Description

Thermo Scientific Fish Serum Blocking Buffer is steelhead salmon serum in PBS that is especially useful as a blocking agent in immunohistochemistry (IHC) and other detection methods involving mammalian samples.

Thermo Scientific Fish Serum Blocking Buffer is steelhead salmon serum in PBS that is especially useful as a blocking agent in immunohistochemistry (IHC) and other detection methods involving mammalian samples. Fish Serum Blocking Buffer is effective at stabilizing solutions and samples used for antibody-binding interactions, while at the same time minimizing the possibility of cross-reaction with mammalian sample components.

Features of Fish Serum Blocking Buffer include:
• Non-mammalian—fish proteins are less likely to have specific binding interactions with antibodies and other mammalian proteins present in typical methods
• Convenient—filtered and stabilized in PBS for compatibility with most assay systems
• Easy to use—can be used as supplied or diluted up to 10-fold as needed
• Flexible - may be used for many different applications, including as a diluent for antibodies

Fish serum offers several advantages over typical blocking buffers. Because salmon is phylogenetically distant from mammals, which are the source of the antibodies and samples used in most experiments, its serum proteins are less likely to have specific binding interactions with proteins used in the experiments. Fish Serum Blocking Buffer is effective at stabilizing solutions and samples used for antibody-binding interactions while at the same time minimizing the possibility of cross-reaction with mammalian sample components. Try it when use of more-standard sera results in background staining in IHC. In addition, this blocker is effective in various cellular imaging protocols based on visible and near-infrared fluorescence detection. It has been used to decrease background and increase signal-to-noise ratios with near-IR fluorescent probes.

Specifications

• Chemical Name or Material: Fish Serum Blocking Buffer
• Concentration: 1X
• For Use With (Application): ELISA
• Physical Form: Liquid
• Quantity: 500 mL

Frequently Asked Questions (FAQs)

How can I reduce background bands in my Western blot?

Optimize the concentration of primary and secondary antibodies. In some cases, increasing the concentration of blocking agent (BSA or non-fat dry milk) or usiing an alternative blocking solution such as Starting Block or SuperBlock may reduce background signal. After incubation with the primary antibody, wash at least 2 times with TBST (include 0.5 M NaCl in one or more of the wash steps). Avoid Nonidet P40 or Triton X-100 in buffers because protein detection is decreased when these detergents are used.

What is the concentration of protein in the Fish Serum Blocking Buffer?

This information is proprietary. The protein concentration in the Fish Serum Blocking Buffer has been optimized for direct usage without further dilution, however if desired, the blocking buffer may be diluted with phosphate-buffered saline. For best results, our recommendation is to empirically determine the optimal concentration to use.

I used a neuron-specific antibody to label my neurons. How can I reduce non-specific antibody binding?

A blocking step should be performed to reduce fluorescence due to non-specific antibody binding. A common blocking step is the addition of a 2-5% solution of bovine serum albumin (fraction V defatted BSA). Another approach employs the addition of a 5-10% solution of serum from the species in which the secondary antibodies were raised. For example, when using goat anti-mouse IgG secondary antibodies, samples may be effectively blocked with 5-10% normal goat serum. To further reduce background fluorescence, the Image-iT FX Signal Enhancer can be included as a pre-blocking step to decrease non-specific labeling due to charge interactions between the dyes on the conjugates and the cellular constituents.
If you are using a secondary antibody make sure that the species of the antibody is not the same as the species of the sample. For example do not use an anti-mouse secondary antibody on mouse tissue.
Titrate the antibody to the lowest concentration you can use and still get adequate signal.
Try using a fluorescently tagged primary antibody because it should give reduced background but be aware this can reduce signal intensity.

After labeling with my antibody, I am seeing non-specific background binding in my cells or tissue. What could be the cause?

There can be many causes, including insufficient blocking, too high a concentration of the primary or secondary antibody, or degraded primary or secondary antibody. A “no-primary antibody” control can help determine if the secondary antibody is at fault. Otherwise, we recommend trying more stringent blocking or lower concentrations of primary and secondary antibodies.

What concentration of my antibody should I use for cell analysis?

An optimal concentration may be between 1-10 µg/mL for cell and tissue labeling for microscopy, or 0.2-5 µg/mL for flow cytometry. A range of concentrations should be tested to determine what is optimal.

I know I need to block my samples against non-specific protein binding of my antibodies, but which blocker should I use?

For blocking cells or tissues you may use 2-5% bovine serum albumin (fraction V, defatted BSA) or 5-10% normal serum of the species matching the host species of the secondary antibody. Other options include a mixture of BSA and serum or other purified proteins. We offer a ready-made blocking solution, BlockAid Blocking Solution (Cat. No. B10710), which is not species-specific. For cell or tissue samples, avoid the use of non-fat dry milk as a blocking agent as it contains a high level of phosphoproteins, histones, and biotin.

Safety and Handling

WARNING: Cancer - www.P65Warnings.ca.gov